rentease/internal/pdf/service.go

package pdf

import (
	"bytes"
	"encoding/json"
	"errors"
	"fmt"
	"io"
	"net/http"
	"os"
	"strconv"

	"github.com/labstack/gommon/log"

	"github.com/rjNemo/rentease/internal/booking"
	u "github.com/rjNemo/underscore"
)

type PdfService struct {
	invoicePath string
	projectId   string
	url         string
	apiKey      string
}

func NewPdfService() *PdfService {
	return &PdfService{
		invoicePath: "index.html",
		projectId:   os.Getenv("HTMLDOCS_PROJECT_ID"),
		url:         os.Getenv("HTMLDOCS_URL"),
		apiKey:      os.Getenv("HTMLDOCS_KEY"),
	}
}

func (ps PdfService) BuildInvoice(b *booking.Booking) error {
	data := struct {
		Context   map[string]any `json:"context"`
		Path      string         `json:"path"`
		ProjectId string         `json:"projectId"`
	}{
		Context: map[string]any{
			"id":               fmt.Sprintf("VFNI%04s", strconv.Itoa(b.Id)),
			"name":             b.Name,
			"phone_number":     b.PhoneNumber,
			"custumers_number": b.CustomerNumber,
			"platform":         b.Platform,
			"from":             b.From.Format("Monday 02 January 2006"),
			"to":               b.To.Format("Monday 02 January 2006"),
			"lines":            b.Items,
			"total": strconv.FormatFloat(u.Reduce(b.Items, func(i booking.Item, sum float64) float64 {
				return sum + i.Price*float64(i.Quantity)
			}, 0.0), 'f', 2, 64),
		},
		Path:      ps.invoicePath,
		ProjectId: ps.projectId,
	}

	payload, err := json.Marshal(data)
	if err != nil {
		log.Warnf("Error marshalling JSON:", err)
		return err
	}

	// build request to third-party API
	req, err := http.NewRequest("POST", ps.url, bytes.NewBuffer(payload))
	if err != nil {
		log.Warnf("Error creating request:", err)
		return err
	}

	req.Header.Set("Authorization", "Bearer "+ps.apiKey)
	req.Header.Set("Content-Type", "application/json")

	client := &http.Client{}
	resp, err := client.Do(req)
	if err != nil {
		log.Warnf("Error sending request:", err)
		return err
	}
	defer resp.Body.Close()

	res := new(struct {
		Url   string `json:"url"`
		Error string `json:"error"`
	})
	body, err := io.ReadAll(resp.Body)
	if err != nil {
		return err
	}

	err = json.Unmarshal(body, res)
	if err != nil {
		log.Warnf("error decoding response: %s", err)
		return err
	}

	if res.Error != "" {
		log.Warnf("error building pdf file %s", err)
		return errors.New(res.Error)
	}

	resp, err = http.Get(res.Url)
	if err != nil {
		log.Warnf("Error retrieving file")
		return err
	}
	defer resp.Body.Close()

	file, err := os.Create("tmp.pdf")
	if err != nil {
		log.Fatal(err)
	}
	defer file.Close()

	body, err = io.ReadAll(resp.Body)
	if err != nil {
		return err
	}

	_, err = file.Write(body)
	if err != nil {
		log.Error("Error copying file content")
		return err
	}
	return nil
}